plot grib data in python

Purdue High Impact Weather Laboratory‎ > ‎Archive‎ > ‎Forecast Verification - EAS 591 - Fall 2012‎ > ‎

install Basemap on coates

http://matplotlib.org/basemap/users/installing.html

#untar the basemap tarball

cd $HOME

mkdir $HOME/GEOS

mkdir -p $HOME/local/lib/python2.7/site-packages

tar -zxvf /usr/rmt_share/baldwin/basemap-1.0.5.tar.gz

cd basemap-1.0.5

#install GEOS

cd geos-3.3.3

export GEOS_DIR=$HOME/GEOS

./configure --prefix=$GEOS_DIR

make; make install

cd $HOME/basemap-1.0.5

module load python/2.7

module load ncl

python setup.py install --prefix=$HOME/local

# add these lines to your .bash_profile

export NETCDF_HOME=/apps/rhel5/graphics/x86_64/gnu/gcc-4.1.2/netcdf-4.1.1

export PYTHONPATH=${PYTHONPATH}:~/local/lib/python2.7/site-packages

export LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:${NETCDF_HOME}/lib

export PATH=${PATH}:${NETCDF_HOME}/bin

python script to print out variable names in GRIB file

/usr/rmt_share/baldwin/EAS591/gribvars.py

#!/usr/bin/env python

import matplotlib.pyplot as plt

import math

import numpy as np

from pylab import *

import Nio

import scipy.ndimage

from optparse import OptionParser

import os

import datetime

import time

import sys

import textwrap

import subprocess

#########################################################################################

file='stage2.20070501.grb'

#open file(s)

gr = Nio.open_file(file,'r',format='grb')

print gr

gr = Nio.open_file(file,'r',format='grb')

print gr

names = gr.variables.keys()

print "Variable names:", names

#dimensions

dims = gr.dimensions

print "dimensions:",dims

#global attributes

attr = gr.attributes.keys()

print "global attributes",attr

data = gr.variables['gridlat_240']

attrib = data.attributes.keys()

print attrib

dx = getattr(data,'Dx')

dy = getattr(data,'Dy')

print dx, dy

python script to read in and plot QPF and observed precip

/usr/rmt_share/baldwin/EAS591/plotpcp.py

#!/usr/bin/env python

import matplotlib

matplotlib.use('Agg')

import matplotlib.pyplot as plt

import numpy as np

from optparse import OptionParser

from pylab import *

import Nio

import scipy.ndimage

import os

from mpl_toolkits.basemap import Basemap

from mpl_toolkits.basemap import cm

from mpl_toolkits.axes_grid import make_axes_locatable

import matplotlib.axes as maxes

#########################################################################################

parser = OptionParser()

parser.add_option("-d", "--fcst_date", dest="date", default="20070501",

help="fcst date", metavar="YYYYMMDD")

(options, args) = parser.parse_args()

file = 'stage2.' + options.date + '.grb'

print file

#open file

gr = Nio.open_file(file,'r')

#read in variables

obs = gr.variables["A_PCP_240_SFC_acc24h"][:]

lats = gr.variables["gridlat_240"][:]

lons = gr.variables["gridlon_240"][:]

# plot precip

fig = plt.figure()

fig.set_size_inches(8,5)

ax = fig.add_axes([0.1,0.1,0.8,0.8])

m = Basemap(projection='lcc',lon_0=-95.,

llcrnrlat=20.,urcrnrlat=50., llcrnrlon=-120.,urcrnrlon=-60.,

lat_1=25.,lat_2=46.,resolution='i',area_thresh=1000.,ax=ax)

m.drawcoastlines(linewidth=0.5)

m.drawstates()

m.drawcountries()

parallels = np.arange(0.,90,5.)

m.drawparallels(parallels,labels=[1,0,0,0],fontsize=10)

meridians = np.arange(180.,360.,5.)

m.drawmeridians(meridians,labels=[0,0,0,1],fontsize=10)

x, y = m(lons,lats)

intervals = [0.1,2,5,10,15,20,25,35,50,75,100,125,150,200,300,400,500]

obsobj = m.contourf(x,y,obs,intervals,cmap=cm.s3pcpn)

colbar = m.colorbar(obsobj,location="right",size="5%",pad=0.05,extend='both',ticks=intervals)

colbar.set_label('mm',rotation='horizontal',fontsize='medium')

titlestr = 'NCEP STAGE2 Accum precip '

plt.title(titlestr, fontsize='medium')

fname = 'stage2.'+options.date+'.png'

plt.savefig(fname)

#close file

gr.close()

# now do the wrf precip

file = 'wrfnssl.' + options.date + '.grb'

print file

#open file

gr = Nio.open_file(file,'r')

#read in variables

fcst = gr.variables["A_PCP_240_SFC_acc24h"][:]

lats = gr.variables["gridlat_240"][:]

lons = gr.variables["gridlon_240"][:]

# plot precip

fig = plt.figure()

fig.set_size_inches(8,5)

ax = fig.add_axes([0.1,0.1,0.8,0.8])

m = Basemap(projection='lcc',lon_0=-95.,

llcrnrlat=20.,urcrnrlat=50., llcrnrlon=-120.,urcrnrlon=-60.,

lat_1=25.,lat_2=46.,resolution='i',area_thresh=1000.,ax=ax)

m.drawcoastlines(linewidth=0.5)

m.drawstates()

m.drawcountries()

parallels = np.arange(0.,90,5.)

m.drawparallels(parallels,labels=[1,0,0,0],fontsize=10)

meridians = np.arange(180.,360.,5.)

m.drawmeridians(meridians,labels=[0,0,0,1],fontsize=10)

x, y = m(lons,lats)

intervals = [0.1,2,5,10,15,20,25,35,50,75,100,125,150,200,300,400,500]

fcstobj = m.contourf(x,y,fcst,intervals,cmap=cm.s3pcpn)

colbar = m.colorbar(fcstobj,location="right",size="5%",pad=0.05,extend='both',ticks=intervals)

colbar.set_label('mm',rotation='horizontal',fontsize='medium')

titlestr = 'WRFNSSL Accum precip '

plt.title(titlestr, fontsize='medium')

fname = 'wrfnssl.'+options.date+'.png'

plt.savefig(fname)

#close file

gr.close()

# plot difference

fig = plt.figure()

fig.set_size_inches(8,5)

ax = fig.add_axes([0.1,0.1,0.8,0.8])

m = Basemap(projection='lcc',lon_0=-95.,

llcrnrlat=20.,urcrnrlat=50., llcrnrlon=-120.,urcrnrlon=-60.,

lat_1=25.,lat_2=46.,resolution='i',area_thresh=1000.,ax=ax)

m.drawcoastlines(linewidth=0.5)

m.drawstates()

m.drawcountries()

parallels = np.arange(0.,90,5.)

m.drawparallels(parallels,labels=[1,0,0,0],fontsize=10)

meridians = np.arange(180.,360.,5.)

m.drawmeridians(meridians,labels=[0,0,0,1],fontsize=10)

intervals = np.arange(-300.,300.,30.)

diffobj = m.contourf(x,y,fcst-obs,intervals,cmap=plt.cm.spectral)

colbar = m.colorbar(diffobj,location="right",size="5%",pad=0.05,extend='both',ticks=intervals)

colbar.set_label('mm',rotation='horizontal',fontsize='medium')

titlestr = 'WRFNSSL-STAGE2 precip '

plt.title(titlestr, fontsize='medium')

fname = 'diff.'+options.date+'.png'

plt.savefig(fname)

# plot a,b,c,d

thresh=1.

a=np.logical_and(fcst>thresh,obs>thresh)

b=np.logical_and(fcst>thresh,obs<=thresh)

c=np.logical_and(fcst<=thresh,obs>thresh)

d=np.logical_and(fcst<=thresh,obs<=thresh)

fig = plt.figure()

fig.set_size_inches(8,5)

ax = fig.add_axes([0.1,0.1,0.8,0.8])

m = Basemap(projection='lcc',lon_0=-95.,

llcrnrlat=20.,urcrnrlat=50., llcrnrlon=-120.,urcrnrlon=-60.,

lat_1=25.,lat_2=46.,resolution='i',area_thresh=1000.,ax=ax)

m.drawcoastlines(linewidth=0.5)

m.drawstates()

m.drawcountries()

parallels = np.arange(0.,90,5.)

m.drawparallels(parallels,labels=[1,0,0,0],fontsize=10)

meridians = np.arange(180.,360.,5.)

m.drawmeridians(meridians,labels=[0,0,0,1],fontsize=10)

intervals = np.arange(-1.,2.,1.)

aobj = m.contourf(x,y,a,intervals,cmap=plt.cm.spectral)

colbar = m.colorbar(aobj,location="right",size="5%",pad=0.05,extend='both',ticks=intervals)

titlestr = 'WRFNSSL-STAGE2 a '

plt.title(titlestr, fontsize='medium')

fname = 'a.'+options.date+'.png'

plt.savefig(fname)

quit()

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